高红移亚毫米星系中星际介质的物理状态

Physical Conditions of the Interstellar Medium in High-redshift Submillimetre Bright Galaxies

随着亚毫米波望远镜的发展,利用这些新的探测设备,人们在亚毫米波段发现了一类高红移且富含尘埃的星系,将其称为亚毫米星系.这类星系的发现革新了我们对星系的演化以及极端条件下的恒星形成过程的认知.这些亚毫米星系是宇宙中最强的星暴星系,其中的恒星形成过程产生的能量接近爱丁顿极限.人们普遍认为这类星系正是近邻宇宙中那些大质量星系的前身天体.但是,很难解释其在高红移为何具有较高的数密度.它们其中非常少的一部分会被处于视线方向上的大质量星系通过引力透镜作用放大变亮.尽管这类处于引力透镜系统中的亚毫米星系十分稀少,但近来人们通过大视场河外巡天,发现了上百个此类天体,这为我们研究高红移亚毫米星系中的星际介质提供了一个令人振奋的新途径.

The discovery of a population of high-redshift dust-obscured submillimeter galaxies (SMGs) from ground-based submillimetre (submm) cameras has revolutionised our understanding of galaxy evolution and star formation in extreme conditions. They are the strongest starbursts in the Universe approaching the Eddington limit, and are believed to be the progenitors of the most massive galaxies today. However, theoretical models of galaxy evolution have even been unable to explain the large number of detections of high-redshift SMGs. A very few among them are gravitationally lensed by a foreground galaxy. Recent wide-area extragalactic surveys have discovered hundreds of such strongly lensed SMGs, opening new exciting opportunities for observing the interstellar medium in these exceptional objects.